Even with Tor, you still leak all your addresses and allow them to be linked together. The only way to be anonymous with any Electrum wallet, watch only or not, is to connect it to your own node/server.
You leak your wallet addresses but tor will mask the IP address in a way the central server will not know the IP address. To have a full node wallet needs over 400 gigibyte and addictional gigabytes daily, that makes people not to have full node wallets. The only way to complete privacy is to have your own electrum server or full node and connect to it instead of the central servers, but not everyone that can afford this.
With tor, you can still try as much as possible to be anonymous to some extent. You can have an offline ways to generate seed phrase, get some private keys and their addresses. Get different wallets like Electrum, Sparrow and some other open source and import the private keys of each addresses on the different wallets.
Like in this order:
- Electrum, private key 1
- Sparrow, private key 2
- Samourai, private key 3
Or generate seed phrase on each wallet and fund just one address. Using tor to connect to each wallet and changing the tor routing connection for each.
With tor I can still be anonymous but it is not like the more privacy that full node wallet can give with ease.